Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Holland you can determine when it's a good idea to plant polygonums by looking at the USDA zone info.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You should not plant polygonums until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant polygonums in Holland is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant polygonums and expect a good harvest is probably August. Any later than that and your polygonums may not have a chance to fully mature. You can get started a little bit earlier by starting your polygonums indoors.

Last Frost Date

In Holland the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

It's important to remember that USDA zone info for Holland may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Holland it frosts late in the year after April 15 be ready to protect your polygonums in the event of a late frost.

USDA Zone Info for Holland

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Holland

You may be interested in your other planting guides for Holland.